Uric acid is a white substance with no taste and no odor, and is produced from purine when cells are decomposed or in the course of energy metabolism. Since higher primates such as human and monkey and a part of fishes and reptiles cannot decompose uric acid, uric acid concentration in the blood gets higher when the synthesis of uric acid is accelerated or the excretion speed of uric acid is decreased in such organisms. Additionally because uric acid is a slightly water-soluble substance, uric acid not dissolvable above the solubility of uric acid in blood or urine is crystallized as sodium urate. Further, the solubility of uric acid is additionally decreased when blood or urine gets acidic or the temperature is lowered. Gout occurring via the deposition of crystallized uric acid in joints or around joints is a disease causing joint disorders, gout knot, urinary calculus and other complications and characteristically involves severe pains.
The Japanese Society of Gout and Nucleic Acid Metabolism defines that a condition at a blood uric acid concentration level exceeding 7.0 mg/dl is hyperuricemia. It is estimated that patients with hyperuricemia at uric acid concentrations of 8.0 mg/dl or more will be 2,000,000 and borderline patients with mild symptoms at uric acid concentrations of 7.0 mg/dl or more will be up to 6,000,000 in Japan. Among the patients with hyperuricemia, the onset of gout is found in about one out of 10. It is estimated currently that there will be 500,000 to 600,000 gout patients in Japan.
Herein, the metabolic syndrome is a syndrome with multiple risk factors and involves the accumulation of organ fats and complications based on accumulated organ fats, such as insulin resistance, abnormal sugar metabolism, abnormal lipid metabolism and hypertension and is therefore a condition readily falling in arteriosclerosis. It is suggested that serum uric acid level is useful as a reference marker to determine the metabolic syndrome. Additionally, it is also indicated that the high level of serum uric acid itself is a risk factor of arteriosclerosis.
As described above, hyperuricemia is not only involved in gout as indicated conventionally but also causes complications of life style-related diseases such as hypertension, hyperlipidemia, abnormal glucose tolerance, and obesity at high frequencies. Hence, attention is now increasingly focused on the prophylaxis and therapeutic treatment of hyperuricemia as a risk factor of cardiovascular diseases and/or a risk marker thereof.
Based on the balance between the generation and excretion of uric acid, hyperuricemia is broadly classified as a uric acid excretion-decreased type (deterioration of the potency of excreting uric acid in urine), excess uric acid generation type (increase of generated uric acid) and a mix type of both of the types described above.
Drugs exist for each disease type of hyperuricemia. For hyperuricemia of the excretion-decreased type, for example, probenecid, bucolome and benzbromarone are used; for hyperuricemia of the excess generation type, alloprinol is used. However, the therapeutic treatment for the decrease of uric acid with these drugs not only requires attention toward adverse actions and drug interactions but also requires deliberate cautions toward the indication thereof to hyperuricemia with none of clinical symptoms such as gout arthritis or gout knot (so-called asymptomatic hyperuricemia). Therefore, a serum uric acid level-decreasing agent from natural origins and without any adverse actions or with relatively less adverse actions is needed.
Regarding active ingredients from natural origins and with an effect on the amelioration of hyperuricemia, patent document 1 describes food compositions containing as the active ingredient dried products and/or extracts of hamamelis and Linonium wrightii O. Kuntze; patent document 2 describes foods or pharmaceutical agents containing as the active ingredient a plant such as meadow sweet, cinnamon, Lippia triphylla, Rhodiola rosea, Rhodiola sachalinensis, Alpinia galangal, nutmeg, St. John's wort, and grape, or propolis; patent document 3 describes plants selected from Origanum vulgare, Mosla chinensis, Elsholtzia ciliate, lemon balm, rosemary, spearmint, peppermint, winter savory, Piper betle and Carmona retusa, and/or extracts of such plants.
Further, non-patent document 1 describes that flavonoids existing in various foods and drinks derived from plants have an effect of inhibiting xanthine oxidase; and non-parent reference 2 describes an action of propolis to inhibit xanthine oxidase and an action derived from the action described above to decrease the level of crystalline uric acid.
Still further, patent document 4 describes lactic acid bacteria or yeast with a potency of decomposing purine to exert an action of decreasing serum uric acid level, and also describes a composition containing at least one selected from such microorganisms.
Residues as byproducts at steps of producing for example liquors, Japanese sakes and distilled spirits, such as sake lees as a byproduct at steps of producing Japanese sake and vinegar (“moromi” in Japanese) as a byproduct at steps of producing for example distilled liquors made from rice (“awamorii” in Japanese), have been used traditionally as raw materials of pickles, soups and drinks. Therefore, the safety profiles of the residues as foods have been certified. However, residues from distillation of distilled spirits (“shochu” in Japanese) as derived from distilled spirits from barley (“oh-mugi shochu” in Japanese), distilled spirits from sweet potatoes (“imo shochu” in Japanese) and distilled spirits from rice (“kome shochu” in Japanese) have mostly been disposed so far via for example disposal in oceans and by returning the residues to soil and burning the residues by incineration. The disposal in oceans is an inexpensive disposal method of the residues from distillation of distilled spirits. However, the disposal in oceans is now regulated by rules following the increase of ecological issues, so that the disposal will be absolutely prohibited in future. Furthermore, the procedure of returning the residues to soil disadvantageously pollutes ground water and rivers, while the incineration disposal is disadvantageous in terms of cost and dioxin generation. In view of such problems, currently, an effective utilization of the residues from distillation of distilled spirits has been investigated in diverse fields.
Among others, residues from distillation of distilled spirits from barley are made from barley as a raw material, and barley is a cereal indispensable for humans since the dawn of history and has been familiar as a safe and healthy food as described in traditional Japanese medical books. Accordingly, it is considered that the residues are highly nutritious materials and are highly safe materials, in particular.
From the standpoint of the effective utilization of the residues from distillation of distilled spirits, the present inventors propose in patent document 5 a method for producing a feed from residues from distillation of distilled spirits.
Additionally as inventions of utilizing a residue from distillation of distilled spirits from barley as a byproduct in the production of distilled spirits from barley as a raw material as made by the inventors, patent document 6 describes that a purified concentrate isolated by subjecting a residue from distillation of distilled spirits from barley as a byproduct in the production of distilled spirits from a raw material barley to a separation procedure to a solid fraction and a liquid fraction to obtain the liquid fraction, subjecting the liquid fraction to an absorption treatment with a synthetic adsorbent to obtain the adsorbed fraction, and eluting the adsorbed fraction with an alkali or an organic solvent has an action of suppressing the onset of orotinic acid-inducing fatty liver and/or D-galactosamine-inducing hepatitis; and patent document 7 describes that the fraction obtained from the residue from distillation of distilled spirits from barley in the same manner as in patent document 6 has an exceedingly great anti-oxidant action. Additionally, patent document 8 describes that the fraction obtained from the residue from distillation of distilled spirits from barley in the same manner as in patent document 6 has an exceedingly great pharmacological action of enhancing memory and learning ability.    Patent document 1: JP-A-2000-83862    Patent document 2 JP-A-2002-121145    Patent document 3: JP-A-2003-252776    Patent document 4: JP-A-2005-507319    Patent document 5: Patent No. 3495429    Patent document 6: JP-A-2003-38153    Patent document 7: JP-A-2004-238453    Patent document 8: JP-A-2004-359608    Non-patent document 1: Biosci. Biotechnol. Biochem., 63(10), 1787-1790, 1999    Non-patent document 2: Yakugaku Zasshi (Japanese Journal of Pharmaceutical Medicine), 125(3), 315-321, 2005